Disclosed are methods, libraries, and samples for quantifying a target analyte in a laboratory sample including the target analyte. The methods typically include the step of estimating the amount of the target analyte in the laboratory sample from mass spectrometric data including signal intensities for the target analyte and one or more internal standards, where the mass spectrometric data are an output of a mass spectrometric analysis of a target sample produced from the laboratory sample and a predetermined amount of the one or more internal standards. The present disclosure also provides a method for analyte quantification. The method comprises adding one or more calibrators to a sample comprising one or more analytes; applying mass spectrometry (MS) to the sample; and using a trained machine learning model to determine an absolute concentration of the one or more analytes.

Disclosed are methods, libraries, and samples for quantifying a target analyte in a laboratory sample including the target analyte. The methods typically include the step of estimating the amount of the target analyte in the laboratory sample from mass spectrometric data including signal intensities for the target analyte and one or more internal standards, where the mass spectrometric data are an output of a mass spectrometric analysis of a target sample produced from the laboratory sample and a predetermined amount of the one or more internal standards. The present disclosure also provides a method for analyte quantification. The method comprises adding one or more calibrators to a sample comprising one or more analytes; applying mass spectrometry (MS) to the sample; and using a trained machine learning model to determine an absolute concentration of the one or more analytes.

Disclosed are methods, libraries, and samples for quantifying a target analyte in a laboratory sample including the target analyte. The methods typically include the step of estimating the amount of the target analyte in the laboratory sample from mass spectrometric data including signal intensities for the target analyte and one or more internal standards, where the mass spectrometric data are an output of a mass spectrometric analysis of a target sample produced from the laboratory sample and a predetermined amount of the one or more internal standards. The present disclosure also provides a method for analyte quantification. The method comprises adding one or more calibrators to a sample comprising one or more analytes; applying mass spectrometry (MS) to the sample; and using a trained machine learning model to determine an absolute concentration of the one or more analytes.

There is provided a specimen analyzer that can measure carry-over without degrading a specimen processing capability. A specimen analyzer according to the present invention measures a first sample including a first specimen and a first internal reference material, subsequently measures a second sample including a second specimen and a second internal reference material, and calculates an amount of the second specimen included in the second sample using an amount of the first internal reference material measured when the first sample has been measured and an amount of the second internal reference material measured when the second sample has been measured.

A method for simultaneously determining fat-soluble vitamins and carotenoids in serum, and belonging to the technical field of analytical chemistry, includes an ionic liquid (IL) or a binary mixed solvent composed of an IL and another solvent is adopted as an extractant; the biological samples are pre-treated by liquid-liquid extraction (LLE) and then detected by high-performance liquid chromatography (HPLC); retinyl acetate and trans-β-apo-8′-carotenal are adopted as the internal standards for fat-soluble vitamins and carotenoids, respectively; and the internal standard method is adopted to establish standard curves for quantification based on the retention time and the UV-Vis absorption spectrum. Compared with the existing methods, in the disclosure, the pretreatment process is simple and easy to be conducted, the sample can be prepared in a short time, and the toxic and harmful organic solvent is used at a reduced amount.

The present disclosure provides compositions, methods, and systems for identifying marked hydrocarbon fluids. These compositions, methods, and systems utilize a gas chromatography marker including a pyrrolidinone. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the pyrrolidinone. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

The present disclosure provides compositions, methods, and systems for identifying marked hydrocarbon fluids. These compositions, methods, and systems utilize a gas chromatography marker including a pyrrolidinone. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the pyrrolidinone. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

The present invention describes a test kit for the detection of fat-soluble vitamins in serum using a method based on high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The internal standard (IS) solution included in the kit is based on methanol, acetonitrile and isopropyl alcohol solvents. Ammonium acetate is added to the IS solution to make it more stable and last for longer storage time. The application of this kit can significantly improve the recovery and detection sensitivity of vitamins A, E, K1 and K2 in serum without additional sample enrichment, make sample preparation process simpler and more efficient, keep processed samples stable for longer time, and lower the overall cost for more accurate and repeatable test results.

A pretreatment method for analyzing dioxin compounds and an analytical method using the same, in which a column packed with polymer beads that are capable of selectively adsorbing dioxin compounds is used in a purification step during pretreatment, thereby remarkably reducing a time required for pretreatment and improving a recovery rate of an internal standard for purification, are provided.

This disclosure provides several methods in LC-MS/MS analysis: (1) a method of LC-MS/MS analysis technique to determine the analyte concentration of a sample wherein an In-Sample Calibration Curve (ISCC) is used instead of an external calibration curve through monitoring of multiple isotopologue transitions of an added stable isotopically labeled (SIL) analyte in each sample via MS/MS in multiple isotopologue reaction monitoring (MIRM) mode; (2) a method of LC-MS/MS analysis to determine the analyte concentration of a sample wherein a One-Sample Multipoint External Calibration Curve (OSMECC) is used instead of a multisample external calibration curve; and (3) a method of LC-MS/MS analysis to determine the analyte concentration of a sample with an analyte concentration beyond the assay's ULOQ wherein isotope sample dilution is used instead of diluting sample physically during sample preparation based on calculating the isotopic abundance of the MIRM channel monitored.